"And that's why it's good to kind of delay the process ... you genuinely gotta trust that they're gonna be able to do the job you're paying them to do," Cowell said. "And like I said, a hit maker, who worked in America and has had experience, I think is crucial to this panel as well."

Two names you won't see added to the show: Katy Perry and Elton John. "Well, he's so grumpy nowadays ... he'd just be moaning the whole time," Simon said of John.